SAN FRANCISCO — A federal judge overturned California's gay marriage ban Wednesday with an unequivocal ruling that could eventually force the U.S. Supreme Court to confront the question of whether same-sex couples have a constitutional right to wed.

Chief U.S. District Judge Vaughn Walker's strongly worded opinion in the landmark case — the first in a federal court to examine if states can lawfully limit marriage to a man and a woman — touched off a celebration outside the courthouse. Later in the day, a jubilant crowd marched through the city that has long been a haven for gays.

The ruling met immediate criticism from Mormon and Catholic church leaders and cheers from gay-rights advocates.

As word of the verdict spread, about 300 people assembled in a West Hollywood park waving rainbow gay pride flags. In New York City, a crowd of about 150 gathered outside a lower Manhattan courthouse. They carried signs saying "Our Love Wins" as organizers read portions of the 136-page decision aloud.

"Moral disapproval alone is an improper basis on which to deny rights to gay men and lesbians. The evidence shows conclusively that Proposition 8 enacts, without reason, a private moral view that same-sex couples are inferior to opposite-sex couples," Walker wrote.

The judge added in the conclusion of the 136-page opinion: "Proposition 8 fails to advance any rational basis in singling out gay men and lesbians for denial of a marriage license."

His ruling came in response to a lawsuit brought by two same-sex couples and the city of San Francisco seeking to invalidate the law as an unlawful infringement on the civil rights of gay men and lesbians. The landmark case is expected to be appealed and could eventually reach the U.S. Supreme Court.

Outside the federal courthouse in San Francisco, a cheer went up among a group of about 70 same-sex marriage supporters carrying small U.S. flags, as a large rainbow-striped flag — the symbol of the gay rights movement — waved overhead.

Ruling on holdDespite the favorable ruling for same-sex couples, gay marriage will not be allowed to resume immediately.

Walker said he would consider while Protect Marriage pursues its appeal suspending an order requiring the state to cease enforcing Proposition 8. He ordered both sides to submit written arguments by Friday on the issue.

"In America, we should uphold and respect the right of people to make policy changes through the democratic process, especially changes that do nothing more than uphold the definition of marriage that has existed since the founding of this country and beyond," said Jim Campbell, a lawyer on the defense team.

Walker heard 13 days of testimony and arguments since January during the first trial in federal court to examine if states can prohibit gays from getting married.

"Proposition 8 perpetuates the stereotype that gays and lesbians are incapable of forming long-term loving relationships and that gays and lesbians are not good parents."

Standing in front of eight American flags at a news conference, the two couples behind the case beamed and choked up as they related their feelings of validation.

"Our courts are supposed to protect our Constitutional rights," lead plaintiff Kris Perry said as Sandy Stier, her partner of 10 years, stood at her side. "Today, they did."

"We are not here to change the world. Equality is something our country has always been about," said co-plaintiff Jeff Zarrillo, who is seeking the right to marry his partner of nine years, Paul Katami. "Today's decision brings Paul and I and so many others like us closer to that equality, too."

California Gov. Arnold Schwarzenegger:"For the hundreds of thousands of Californians in gay and lesbian households who are managing their day-to-day lives, this decision affirms the full legal protections and safeguards I believe everyone deserves. At the same time, it provides an opportunity for all Californians to consider our history of leading the way to the future, and our growing reputation of treating all people and their relationships with equal respect and dignity."

California Attorney GeneralJerry Brown:"In striking down Proposition 8, Judge Walker came to the same conclusion I did when I declined to defend it. Proposition 8 violates the equal protection guarantee of the Fourteenth Amendment of the United States Constitution by taking away the right of same-sex couples to marry, without a sufficient governmental interest."

House Speaker Nancy Pelosi, D-Calif.: "We must continue to fight against discriminatory marriage amendments and work toward the day when all American families are treated equally."

Sen. Dianne Feinstein, D-Calif.: Anticipating a Supreme Court hearing, "The journey is not over, but today is a day to celebrate this historic victory for equal marriage rights."

San Francisco Mayor Gavin Newsom: "Today's decision is a victory for the fundamental American idea enshrined in our Constitution that separate is not equal and that all people deserve equal rights and treatment under the law. It is a victory for the thousands of California couples, their families and friends whose lives and loving, committed relationships have once again been affirmed in the eyes of the law."

Attorney Gloria Allred: "This may be a temporary victory but it's sweet. I hope that no stay will be granted because I know what it means to gay and lesbian couples who wish to marry and I agree that they suffer irreparable harm for every day they are denied the right to marry."

The White House: "The President has spoken out in opposition to Proposition 8 because it is divisive and discriminatory. He will continue to promote equality for LGBT Americans."

Michael Purdy, spokesman for The Church of Jesus Christ of Latter-day Saints, which had urged its top leaders to in California congregations top ask members to vote for Proposition 8: "California voters have twice been given the opportunity to vote on the definition of marriage in their state and both times have determined that marriage should be recognized as only between a man and a woman. We agree. Marriage between a man and woman is the bedrock of society. "We recognize that this decision represents only the opening of a vigorous debate in the courts over the rights of the people to define and protect this most fundamental institution — marriage."

Cardinal Francis George of the U.S. Conference of Catholic Bishops: "Marriage between a man and a woman is the bedrock of any society. The misuse of law to change the nature of marriage undermines the common good. It is tragic that a federal judge would overturn the clear and expressed will of the people in their support for the institution of marriage. No court of civil law has the authority to reach into areas of human experience that nature itself has defined."

Eric Risberg
/
AP

Opponents of Proposition 8 cheer outside U.S. District Court in San Francisco on Wednesday after hearing of the judge's ruling overturning California's same-sex marriage ban.

Sen. James Demint, R-S.C.: "Today's wrongful court decision is another attempt to impose a secular immorality on the American people who keep voting to preserve traditional marriage. Traditional marriage has been the foundation of civil society for centuries and we cannot simply toss it aside to fit the political whims of liberal activists with gavels."

SaveCalifornia.com President Randy Thomasson: "Natural marriage, voter rights, the Constitution, and our republic called the United States of America have all been dealt a terrible blow. Judge Walker has ignored the written words of the Constitution, which he swore to support and defend and be impartially faithful to, and has instead imposed his own homosexual agenda upon the voters, the parents, and the children of California. This is a blatantly unconstitutional ruling because marriage isn't in the U.S. Constitution. The Constitution guarantees that state policies be by the people, not by the judges, and also supports states' rights, thus making marriage a state jurisdiction."

Tony Perkins, president, Washington-based Family Research Council: "(The ruling has) almost left me speechless ... This has now become a national case. Using the courts to inject this radical social policy solves nothing and it only inflames the political passion of people and so I think this is far from over ... That they would find a right to same-sex marriage in the constitution is just absurd."

Luke Otterstad, 24, of Sacramento, outside the courthouse with his fiance, Nadia Shayka, 22, wearing T-shirts that read "bride" and "groom": "I'm very upset. I feel like I don't live in America."

Case background
The ruling puts Walker at the forefront of the gay marriage debate. The longtime federal judge was appointed by President Ronald Reagan.

Prop 8, which outlawed gay marriages in California five months after the state Supreme Court legalized them, passed with 52 percent of the vote in November 2008 following the most expensive campaign on a social issue in U.S. history.

The plaintiffs in the California case presented 18 witnesses. Academic experts testified about topics ranging from the fitness of gay parents and religious views on homosexuality to the historical meaning of marriage and the political influence of the gay rights movement.

Former U.S. Solicitor General Theodore Olson delivered the closing argument for opponents of the ban. He told Judge Walker that tradition or fears of harm to heterosexual unions were legally insufficient grounds to discriminate against gay couples.

Olson teamed up with David Boies to argue the case, bringing together the two litigators best known for representing George W. Bush and Al Gore in the disputed 2000 election.

Defense lawyers called just two witnesses, claiming they did not need to present expert testimony because U.S. Supreme Court precedent was on their side. The attorneys also said gay marriage was an experiment with unknown social consequences that should be left to voters to accept or reject.

Former U.S. Justice Department lawyer Charles Cooper, who represented the religious and conservative groups that sponsored the ban, said cultures around the world, previous courts and Congress all accepted the "common sense belief that children do best when they are raised by their own mother and father."

In an unusual move, the original defendants, Brown, the state attorney general, and Schwarzenegger refused to support Proposition 8 in court.

That left the work of defending the law to Protect Marriage, the group that successfully sponsored the ballot measure that passed with 52 percent of the vote after the most expensive political campaign on a social issue in U.S. history.

The verdict was the second in a federal gay marriage case to come down in recent weeks. A federal judge in Massachusetts decided last month the state's legally married gay couples had been wrongly denied the federal financial benefits of marriage because of a law preventing the U.S. government from recognizing same-sex unions.

CARL QUINTANILLA, anchor:Today opponents of same-sex marriage are preparing their legal appeals now that a
federal judge
in
California
has ruled that laws against it are unconstitutional.
NBC
's justice correspondent
Pete Williams
has more.
Pete
, good morning.

PETE WILLIAMS reporting:Carl
,
gay marriage
has been debated in the states for more than two decades, but this is the first time that a
federal judge
has ruled that banning it violates the
US Constitution
, and that's a ruling with potentially nationwide implications. Outside the
San Franciscofederal
courthouse, advocates of
gay rights
cheered the history-making ruling.

Unidentified Woman:We've had a very
happy life
together and we want to make sure that the next generation has a
happy life
, too.

WILLIAMS:The ruling came in a
legal battle
launched by two gay couples in
California
against
Proposition 8
, approved two years ago by 52 percent of the
state
's voters.

WILLIAMS:Passed after
gay marriage
became legal in
California
, it amended the
state constitution
declaring that marriage can only exist between
a man and a woman
. But the judge struck that down, ruling that
Prop
8 violates the
US Constitution
's guarantee of
equal rights
, treating same-sex couples differently without a good enough legal reason.
Federal Judge Vaughn Walker
said "the time has passed when the roles of the genders in marriage were distinct," when marriages were male-dominated. "Marriage under law" now, he says, "is a union of equals. Evidence from the trial, the judge said, showed that "
same-sex
parents are of equal quality" and that "
Proposition 8
makes it no more likely that opposite-sex couples will marry and raise children." A prominent Republican lawyer,
Ted Olsen
, surprised his fellow conservatives by taking on the case, arguing for the gay couples.

Mr. TED OLSEN (Lawyer for Gay Couples):We have other battles ahead of us, but with this decision carefully analyzing the evidence we are well on our way toward an ultimate victory.

WILLIAMS:But opponents of
gay marriage
who supported
Proposition 8
denounce the ruling and began preparing to fight back.

Mr. RANDY THOMASSON (Prop Supporter):The judge has chucked the
Constitution
, imposed his own agenda. He's made a lot of people happy in the
gay community
in
San Francisco
, but he is the most dangerous type of judge in
America
.

WILLIAMS:There won't be any new
gay marriages
right away in
California
. The judge put a temporary hold on his own ruling as the appeals begin in a case that may ultimately wind up at the
US Supreme Court
where a decision there